Toys and other devices that discharge projectiles by release of a compressed or stretched spring or other means to compress air are well known and are disclosed in earlier patents. Safety valves are also known. By way of example, U.S. Pat. No. 1,441,975, for a “Pneumatic Toy Pistol” issued in 1923 to Edelin purports to disclose an air gun where compressed air is created by a piston being driven in a cylinder by an expanding compressed spring, and includes a valve and a BB-like projectile in a barrel. The valve includes a first stationary tube having an opening, the first tube being located at the top end of the cylinder, and a second tube slidable in the first tube and also having an opening. The opening in the second tube is misaligned with the opening in the first tube when the valve is closed and the two openings are aligned when the valve is open. Alignment of the openings is accomplished when a nut located at the top of the piston engages a spring biased pin attached to the second tube. Typically, the valve is biased closed. Engagement occurs when the piston reaches the end of its upward movement in the cylinder such that the open valve allows a blast of compressed air from the cylinder to exit through the valve, impinge on the projectile and cause its discharge.
U.S. Pat. No. 5,343,850 for a “Double Shot Projectile Launcher” issued in 1994 to Steer purports to disclose a double barrel launcher using a bellows for generating a blast of compressed air. The path of the compressed air is determined by manipulation of a trigger that operates a slide valve. The slide valve aligns openings to clear an air path to one of two projectile supporting launch tubes. The air path is blocked when the slide valve misaligns the openings to the launch tube.
A safety valve appears in a patent issued to Nin and D'Andrade, U.S. Pat. No. 5,515,837, granted in 1996, and entitled “Safety Nozzle For Multi-Shot Projectile Shooting Air Gun,” and in U.S. Pat. No. 5,529,050, also issued in 1996 to D'Andrade entitled “Safety Nozzle For Projectile Shooting Air Gun.” The '837 and '050 patents purport to describe a toy air gun safety valve for firing soft foam darts where the valve does not open unless the dart inserted into a launch tube has a predetermined shape that matches a configuration of the valve to enable the dart to push the valve to an open position. The '837 patent also discloses a revolving launch tube magazine, a series of spring biased pins on the magazine with one pin besides each of the launch tubes, a second valve in the form of a hinged flap, and a trigger. Pulling the trigger discharges a dart and rotates the magazine to align another tube of the magazine in front of a pressurized air tank. When the magazine revolves, a spring biased pin on the magazine next to the tube extends outward to swing the hinged flap from a closed position to an open position whether or not the launch tube is loaded. Compressed air generated by the air gun passes through the second valve and then through the safety valve in an axial direction.
Two more recent patents to Bligh, Mead and Brown, U.S. Pat. No. 7,287,526 and U.S. Pat. No. 7,481,209, both entitled “Toy Projectile Launcher With Slidable Outer Cylinder and Stationary Inner Compression Member,” the later patent being a divisional of the earlier patent, purport to disclose a safety valve for an air gun. Moving a slide generates a blast of compressed air and, once actuated, the air flows to the valve in an axial direction. A recently published U.S. Application, No. 2011/0146645, for a “Toy Air Gun” listing Chor-Ming Ma as inventor, purports to disclose a fixed multiple barrel device with a piston and cylinder arrangement. A pressure chamber is located at the front end of the piston and cylinder arrangement, and a rotatable disc is located in the pressure chamber with a single port that is indexed with each discharge to move to the next barrel. Compressed air created by the piston enters the pressure chamber and exits axially through the single port.
These patents and application and the devices disclosed are of some interest, however, they do not teach an efficient safety valve.